cmd下，如何在文本的指定行添加内容

参考出处:http://bbs.wuyou.com/forum.php?mod=viewthread&tid=202142&page=1

第二行和倒数第二行插入新的一行（内容123)

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@echo off
setlocal ENABLEDELAYEDEXPANSION
set n=0
set aa=0
for /f "delims=" %%a in (c:abc.txt) do set /a n=!n!+1
for /f "delims=" %%a in (c:abc.txt) do (
set /a aa=!aa!+1
set /a n=!n!-1
echo %%a >>c: mp.txt
if !aa!==1 echo 123 >>c: mp.txt
if !n!==1 echo 123 >>c: mp.txt
)
del /q c:abc.txt
ren c: mp.txt abc.txt
pause
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如果只是添加123而不是插入新行，方法类似。比如在第二行和倒数第二行开头添加123：
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@echo off
setlocal ENABLEDELAYEDEXPANSION
set n=0
set aa=0
for /f "delims=" %%a in (c:abc.txt) do (
set /a aa=!aa!+1
if !aa!==2 (echo 123%%a >>c: mp.txt) else echo %%a >>c: mp.txt
)
for /f "delims=" %%a in (c: mp.txt) do set /a n=!n!+1
for /f "delims=" %%a in (c: mp.txt) do (
set /a n=!n!-1
if !n!==1 (echo 123%%a >>c: mp1.txt) else echo %%a >>c: mp1.txt
)
del /q c:abc.txt
del /q c: mp.txt
ren c: mp1.txt abc.txt
pause
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